Lameness in lambs and the many challenges facing sheep farmers

Lamb numbers are down on the average in many regions, while a shortage of medication has caused some concerns for flock keepers. Independent sheep consultant, Kate Phillips offers some seasonal commentary and outlines some suggestions for minimising lameness.

Scanning figures tended to be disappointing this season, largely due to the lack of rainfall, which limited grazing availability in the run up to tupping time, said Mrs Phillips. Meanwhile, it is possible that supply issues with some veterinary medicines could compromise sheep health in the months to come for some producers.

“The reasons behind the lack of availability of several standard preventative sheep health treatments are unclear, but it is very unfortunate,” she said. “The industry is being encouraged to improve sheep health and welfare and some of the points of action include preventative medicines.

“I have heard reports that some producers could not access timely supplies of Heptavac P Plus, for example. This is an important treatment for protecting against some of the major clostridial diseases. The vaccine for toxoplasmosis was also unavailable in some regions and this may have had a negative impact on productivity, due to a higher incidence of abortion.

Kate Phillips, independent sheep consultant

“Yet another shortage was experienced more recently in terms of the orf vaccine, which is important for controlling the disease in ewes and in young lambs. We can only hope that supply chain issues are not going to become a regular feature, as they are not good for animal welfare or for farm profitability. Maintaining a high standard of livestock health is also important in the drive to reduce carbon emissions, since animals that are fit and well have a greater level of production efficiency.”

Mrs Phillips referred to the Farm Animal Welfare Council’s sheep targets from 2011, which aimed for a five per cent lameness maximum in sheep by 2016 and two per cent or lower by 2021.

“The Five-point Lameness Plan was developed to help producers reach these targets. It includes vaccination, quarantine, culling, avoidance and treatment and is split into three sections: establishing immunity, building resilience and reducing disease challenge. A significant number of producers have managed to reach the less than two per cent target on the farm at any one time, but there is still work to do on many units.”

Footrot control is a major element of the Plan and routine vaccination will go a long way to reducing lameness when used alongside other aspects of best practice; isolating infected sheep, treating quickly and culling repeat offenders, she stressed.

The wet spring has increased the risk of footrot in lambs

“It is not a good idea to opt in and out of using the footrot vaccine, as the best results are achieved through administration on a routine annual basis – the standard timing for vaccination is pre-tupping or pre-housing. The obvious benefit is to the sheep, but producers who use it habitually have remarked on the reduction in labour, as it takes a lot of time to catch and treat lame sheep.

“Studies have shown that the footrot vaccine can also reduce the incidence of CODD (contagious ovine digital dermatitis), which can lead to severe lameness and a rapid loss of body condition. Any ewe diagnosed with these conditions should be isolated, where possible, and only returned to the flock when she is walking soundly and free of foot lesions.”

A sheep with footrot should be given a long-acting antibiotic and the foot treated topically with an antibiotic spray, advised Mrs Phillips.

“Recent scientific studies have proved beyond doubt that foot-trimming should be kept to a minimum. This recommendation also applies to lame sheep, as trials have shown that recovery time will be faster without foot trimming.”

The wet spring may have increased the risk of lambs suffering from scald, which is the preliminary condition to footrot.

“Studies have shown that getting on top of footrot will help to reduce the incidence of scald. At the first sign of scald, sheep should be walked through a footbath containing three per cent formalin solution or held in a ten per cent zinc sulphate footbath for five minutes-plus.

“If foot bathing stands a chance of working, feet must be clean before entry and therefore a prior footbath containing just water will usually be required. After the treatment, sheep should be left on hard standing for up to an hour to allow time for the feet to dry, before being returned to dry pasture. Any other system will mean that the treatment will be virtually ineffective and the operation will be a waste of both time and money.

“A lame sheep will not achieve the required feed intake for growth and productivity and the pain of the condition can be severe. Lameness is the most obvious sign of poor welfare, so to maintain the reputation of the industry everyone needs to have lameness at the top of their disease prevention priorities,” said Mrs Phillips.